// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)/* Copyright (c) 2021 Facebook */#include <stdint.h>#include <stdlib.h>#include <stdio.h>#include <errno.h>#include <linux/err.h>#include "hashmap.h"#include "libbpf_internal.h"#include "strset.h" struct strset {	void *strs_data;	size_t strs_data_len;	size_t strs_data_cap;	size_t strs_data_max_len; 	/* lookup index for each unique string in strings set */	struct hashmap *strs_hash;}; static size_t strset_hash_fn(long key, void *ctx){	const struct strset *s = ctx;	const char *str = s->strs_data + key; 	return str_hash(str);} static bool strset_equal_fn(long key1, long key2, void *ctx){	const struct strset *s = ctx;	const char *str1 = s->strs_data + key1;	const char *str2 = s->strs_data + key2; 	return strcmp(str1, str2) == 0;} struct strset *strset__new(size_t max_data_sz, const char *init_data, size_t init_data_sz){	struct strset *set = calloc(1, sizeof(*set));	struct hashmap *hash;	int err = -ENOMEM; 	if (!set)		return ERR_PTR(-ENOMEM); 	hash = hashmap__new(strset_hash_fn, strset_equal_fn, set);	if (IS_ERR(hash))		goto err_out; 	set->strs_data_max_len = max_data_sz;	set->strs_hash = hash; 	if (init_data) {		long off; 		set->strs_data = malloc(init_data_sz);		if (!set->strs_data)			goto err_out; 		memcpy(set->strs_data, init_data, init_data_sz);		set->strs_data_len = init_data_sz;		set->strs_data_cap = init_data_sz; 		for (off = 0; off < set->strs_data_len; off += strlen(set->strs_data + off) + 1) {			/* hashmap__add() returns EEXIST if string with the same			 * content already is in the hash map			 */			err = hashmap__add(hash, off, off);			if (err == -EEXIST)				continue; /* duplicate */			if (err)				goto err_out;		}	} 	return set;err_out:	strset__free(set);	return ERR_PTR(err);} void strset__free(struct strset *set){	if (IS_ERR_OR_NULL(set))		return; 	hashmap__free(set->strs_hash);	free(set->strs_data);	free(set);} size_t strset__data_size(const struct strset *set){	return set->strs_data_len;} const char *strset__data(const struct strset *set){	return set->strs_data;} static void *strset_add_str_mem(struct strset *set, size_t add_sz){	return libbpf_add_mem(&set->strs_data, &set->strs_data_cap, 1,			      set->strs_data_len, set->strs_data_max_len, add_sz);} static long strset_str_append(struct strset *set, const char *s){	uintptr_t old_data = (uintptr_t)set->strs_data;	size_t old_data_len = set->strs_data_len;	uintptr_t old_s = (uintptr_t)s;	long len = strlen(s) + 1;	void *p; 	/*	 * Hashmap keys are always offsets within set->strs_data, so to even	 * look up some string from the "outside", we need to first append it	 * at the end, so that it can be addressed with an offset. Luckily,	 * until set->strs_data_len is incremented, that string is just a piece	 * of garbage for the rest of the code, so no harm, no foul. On the	 * other hand, if the string is unique, it's already appended and	 * ready to be used, only a simple set->strs_data_len increment away.	 */	p = strset_add_str_mem(set, len);	if (!p)		return -ENOMEM; 	/*	 * The set->strs_data might have reallocated and if 's' pointed	 * to an internal string within the old buffer, then it became	 * dangling and needs to be reconstructed before the copy.	 */	if (old_data && old_data != (uintptr_t)set->strs_data &&	    old_s >= old_data && old_s < old_data + old_data_len)		s = set->strs_data + (old_s - old_data); 	memcpy(p, s, len); 	return len;} /* Find string offset that corresponds to a given string *s*. * Returns: *   - >0 offset into string data, if string is found; *   - -ENOENT, if string is not in the string data; *   - <0, on any other error. */int strset__find_str(struct strset *set, const char *s){	long old_off, new_off, len; 	len = strset_str_append(set, s);	if (len < 0)		return len; 	new_off = set->strs_data_len; 	if (hashmap__find(set->strs_hash, new_off, &old_off))		return old_off; 	return -ENOENT;} /* Add a string s to the string data. If the string already exists, return its * offset within string data. * Returns: *   - > 0 offset into string data, on success; *   - < 0, on error. */int strset__add_str(struct strset *set, const char *s){	long old_off, new_off, len;	int err; 	len = strset_str_append(set, s);	if (len < 0)		return len; 	new_off = set->strs_data_len; 	/* Now attempt to add the string, but only if the string with the same	 * contents doesn't exist already (HASHMAP_ADD strategy). If such	 * string exists, we'll get its offset in old_off (that's old_key).	 */	err = hashmap__insert(set->strs_hash, new_off, new_off,			      HASHMAP_ADD, &old_off, NULL);	if (err == -EEXIST)		return old_off; /* duplicated string, return existing offset */	if (err)		return err; 	set->strs_data_len += len; /* new unique string, adjust data length */	return new_off;}